Industrial control systems, such as standard industrial control systems (ICS) or programmable automation controllers (PAC), include various types of control equipment used in industrial production, such as supervisory control and data acquisition (SCADA) systems, distributed control systems (DCS), programmable logic controllers (PLC), and industrial safety systems certified to safety standards such as IEC1508. These systems are used in industries including electrical, water and wastewater, oil and gas production and refining, chemical, food, pharmaceuticals and robotics. Using information collected from various types of sensors to measure process variables, automated and/or operator-driven supervisory commands from the industrial control system can be transmitted to various actuator devices such as control valves, hydraulic actuators, magnetic actuators, electrical switches, motors, solenoids, and the like. These actuator devices collect data from sensors and sensor systems, open and close valves and breakers, regulate valves and motors, monitor the industrial process for alarm conditions, and so forth.
In other examples, SCADA systems can use open-loop control with process sites that may be widely separated geographically. These systems use Remote Terminal Units (RTUs) to send supervisory data to one or more control centers. SCADA applications that deploy RTU's include fluid pipelines, electrical distribution and large communication systems. DCS systems are generally used for real-time data collection and continuous control with high-bandwidth, low-latency data networks and are used in large campus industrial process plants, such as oil and gas, refining, chemical, pharmaceutical, food and beverage, water and wastewater, pulp and paper, utility power, and mining and metals. PLCs more typically provide Boolean and sequential logic operations, and timers, as well as continuous control and are often used in stand-alone machinery and robotics. Further, ICE and PAC systems can be used in facility processes for buildings, airports, ships, space stations, and the like (e.g., to monitor and control Heating, Ventilation, and Air Conditioning (HVAC) equipment and energy consumption). As industrial control systems evolve, new technologies are combining aspects of these various types of control systems. For instance, PACs can include aspects of SCADA, DCS, and PLCs.
Within industrial control systems, communications/control modules typically communicate with field devices (e.g., actuators, sensors, and the like) via input/output modules. Technical advances have created a demand for enhanced connectivity between field devices and higher level enterprise and industrial systems and a greater need for connectivity among the devices themselves. In this regard, industrial systems are evolving in a similar manner to the “internet of things” but with much higher security, reliability, and throughput requirements. Robust and secure input/output modules are needed to accommodate the emerging needs in industrial communications and control systems.